An inflatable vehicle occupant restraint, such as an air bag, is inflated upon the occurrence of a vehicle collision. Inflation fluid is directed to flow from a source of inflation fluid into the air bag to inflate the air bag. The inflation fluid inflates the air bag from a folded, stored condition to an inflated condition in which the air bag extends into the vehicle occupant compartment. When the air bag is inflated into the vehicle occupant compartment, it restrains an occupant of the vehicle from forcefully striking parts of the vehicle.
The air bag is part of an air bag module which is mounted in the vehicle. The air bag module includes a reaction canister which contains the air bag in the stored condition. The reaction canister has parts for fastening the air bag module to the vehicle, and supports the source of inflation fluid adjacent to the air bag. The reaction canister also has a deployment opening through which the air bag emerges when it is inflated. A deployment door covers the deployment opening in the reaction canister. The deployment door is opened out of the path of movement of the air bag when the air bag is inflated outward from the reaction canister and into the vehicle occupant compartment.